help on unusual well scale

We pulled a pump yesterday and found some unusual scaling in the well. The scale had a jelly-like consistency and is brown to red in color. It is thick. Where the drop pipe is submerged it is half an inch thick and at places it gets up to one and a half inches thick. The well is made in the Fox Hills formation which is bedrock sand. I believe it is part of the Fort Union formation. Below are pictures and typical fox hills water chemistry.

The well is around 1600â€™ deep. The swl is 200 and pwl is 600â€™. It has a 40 hp Grundfos pump on 3â€ galvanized drop pipe. BTW the Grundfos failed.

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Jelly-like substances are often hydrates which are salts with a lot of "water of hydration" attached to the molecules. There is probably a lot of water in addition to the water of hydration.

It may also be a product of an iron based bacteria that is feeding off the iron in the pipe. The galvanizing is probably gone near the water/air interface.

I suggest taking your sample to the water lab that you usually use. They can probably dilute it and then test it like a water sample to tell you what's in it. They probably have some ideas from their experience.

I am thinking that this must be an extreme case of irb growth. Our well service crew added five pounds of chlorine pellets to the well after the pump was pulled and before it was reset. The pump had failed and a new one is on order. Unless there are other ideas along the way I will post our finding when the well is pulled to put on the new fluid end. If this was an irb, then we should see a difference in the amount of slime after that shock chlorination. The only thing that really concerns me is that this amount of buildup could occur in less then a year.

You can look into a BARTS test kit, they identify a number of different types of bacteria. The tests can take a month though.

IRB eats iron/steel, 70% of the Titanic is gone because of IRB. The guy that invented the BARTS tests used them on the Titanic. When a colony eats itself out of its food source the colony dies off and the iron content in the water will increase; until then it can decrease. Shocking the well can make the bacteria problem worse due to slime formation that chlorine can not penetrate due to the formation of encrustations. On well screen that will reduce the production of the well and the bacteria love the high velocity areas of screen. Adding chlorine to water raises the pH, that decreases the disinfection properties of chlorine. So IOWs, shocking can make the problem worse. If you look at the pH in that analysis, it is already way too high for chlorine to do much disinfecting.

You are right. I think we are going to look into using Johnsonâ€™s NW410 pH buffer. I think that this will improve our disinfection in water wells. I started to look at our well and 90% have a pH higher than 8.0.